160 NATURAL HISTORY 



still continues in this garden; and retired under ground about 

 the twentieth of November, and came out again for one day on 

 the' thirtieth: it lies now buried in a wet swampy border 

 under a wall facing to the south, and is enveloped at present 

 in mud and mire ! 



Here is a large rookery round this house, the inhabitants of 

 which seem to get their livelihood very easily; for they spend 

 the greatest part of the day on their nest-trees when the 

 weather is mild. These rooks retire every evening all the 

 winter from this rookery, where they only call by the way, as 

 they are going to roost in deep woods : at the dawn of day 

 they always revisit their nest-trees, and are preceded a few 

 minutes by a flight of daws, that act, as it were, as their 

 harbingers. 



I am, &c. 



LETTER XVIII. 



TO THE SAME. 



Selborne, Jan. 29, 1774. 



DEAR SIR, 



THE house-swallow, or chimney-swallow, is undoubtedly the 

 first comer of all the British hirundines; and appears in 

 general on or about the thirteenth of April, as I have re- 

 marked from many years observation. Not but now and 

 then a straggler is seen much earlier: and, in particular, 

 when I was a boy I observed a swallow for a whole day 

 together on a sunny warm Shrove Tuesday ; which day could 

 not fall out later than the middle of March, and often hap- 

 pened early in February. 



It is worth remarking that these birds are seen first about 

 lakes and mill-ponds; and it is also very particular, that if 

 these early visitors happen to find frost and snow, as was the 

 the case of the two dreadful springs of 1770 and 1771, they 

 immediately withdraw for a time. A circumstance this much 

 more in favour of hiding than migration; since it is much 



